The present invention relates generally, to a medical tool for tissue characterization, and specifically, to an integrated tool, having a tissue-type sensor, for determining the tissue type at an incision edge, and a distance-measuring sensor, for determining the distance to an interface with another tissue type. The tool is operable for confirming an existence of a clean margin of healthy tissue around an excised tumor, and for determining the width of the margin.
When a malignant tumor is found in a breast, the patient currently has two primary treatment options, 1) mastectomy or 2) breast conserving therapy, which means, lumpectomy, followed by radiation therapy. Generally, breast conserving therapy is indicated for patients with Stage T1 or T2 cancers, of between less then about 0.5 and about 5 cm in greatest dimension.
To localize the tumor within the breast, a radiologist may place a guide wire under x-ray or ultrasound guidance, so that the proximal tip of the guide wire, with respect to the tissue, is in the tumor. Alternatively, an imaging modality alone, for example, mammography, CT, ultrasound, or another imaging modality may be used to locate the tumor. The patient is then transported to the operating room, where the surgeon uses the guide wire, or the image, or palpation to locate the tumor in the breast and to excise a portion of tissue including the cancerous portion and a layer of healthy tissue surrounding the cancerous portion.
The layer of healthy tissue must enclose the cancerous portion, to ensure that all the malignancy has been removed. This layer is often referred to as a “clean margin.” Although generally dependent on the size and shape of the malignant tumor that is being removed, a desired depth of the clean margin may range from 1 cell layer, or about 40 microns, to 10 mm.
Typically the surgeon uses a scalpel and (or) an electrosurgical cutting device to remove a tissue portion enclosing the tumor, in one piece, and manage bleeding. The removed portion is transported to the pathologist, who samples the margins, histologically, at specific and suspicious points, for example, at one or a few representative points on each face of the portion, to assess whether the cancer has been completely removed from the body. If the pathologists deems that cancer cells are too close to the edge of the portion, i.e., if he deems the margin infected, a re-excision is recommended, and the patient must undergo a second surgical procedure to remove more of the tissue.
There are several problems with conventional breast conserving therapy.    1. There are technical challenges associated with placement of the guide wire tip, and the radiologist may not place the guide wire properly through the lesion. It is particularly difficult to place the guide wire at the correct depth. Also, when the guide wire is placed under x-ray guidance, the breast is compressed. When the breast is decompressed for the surgical excision, the guide wire can move, resulting in inaccurate placement thereof. Finally, the guide wire placement procedure is uncomfortable to the patient and logistically challenging; the procedure must be coordinated with the time of surgery. Often, the easiest path for the radiologist to place the guide wire is different from the best surgical approach, so the surgeon cannot follow the guide wire down to the tumor.    2. It is difficult to estimate correctly the full extent of the disease and the exact volume of the cancerous portion of the tumor, especially with non-palpable lesions. Non-palpable lesions are similar in their properties to normal tissue, hence harder to detect by ultrasound and mammography. Thus, the guide wire may be inaccurately placed. To compensate for the imprecision in determining the extent of the disease, the surgeon must remove much more tissue than would be required if the full extent of the cancer could be imaged in real-time. This leads to a negative impact aesthetically and emotionally on the patient.
U.S. Pat. No. 6,546,787 to Schiller et al., whose disclosure is incorporated herein by reference, provides an apparatus and method for detecting a distance from a tissue edge to a malignant tissue, enclosed therein. The apparatus comprises a needle having a strain gage, mounted on one of the needles walls. Strain signals are collected as the needle is moved through the tissue. The needle is inserted at different points to allow data collection from different points within the tissue. The data is sent together with its spatial coordinates to a computerized system, which provides an image of the structure of the examined tissue.
WO Patent 9712553 to Changus et al., whose disclosures is incorporated herein by reference, provides an apparatus for marking a predetermined margin around a tumor that is contained within a healthy tissue. The apparatus includes a needle to be inserted into the patient's body towards the malignant tissue. The needle contains margin wires that are to create a cage containing the malignant tissue within it. The needle is to reach a predetermined distance of between 7 and 13 mm and preferably 10 mm from the malignant tissue before the wires are deployed to create the cage. The cage is then used to guide the surgeon performing a lumpectomy procedure, as to the portion of tissue to be excised and its location, so that the removed tissue will include the malignant tissue with a sufficient clean margin around it. The drawback of such a procedure is that it requires exact knowledge as to the location of the malignant tissue and its boundaries while creating the cage.
US Patent applications 20040168692 and 20020059938, and U.S. Pat. Nos. 6,752,154, 6,722,371, 6,564,806, 6,405,733, all to Fogarty, et al., all entitled, “Device for accurately marking tissue,” and all of whose disclosures are incorporated herein by reference, describe methods and a device for fixedly yet removably marking a volume of tissue containing a suspect region for excision. Additionally they describe methods for deployment of the device and its excision along with the marked tissue volume. At least one locator element is deployed into tissue and assumes a predetermined curvilinear shape to define a tissue border containing a suspect tissue region along a path. The locator element path preferably encompasses the distal-most portion of the tissue volume, with respect to the tool, without penetrating that volume. Multiple locator elements may be deployed to further define the tissue volume along additional paths defining the tissue volume border that do not penetrate the volume. Other localization wire embodiments of the invention are disclosed in which the tissue volume may be penetrated by a portion of the device. Polar and tangential deployment configurations as well as a locator element that may be cold-formed by a die in the distal portion of the deployment tube into a permanent accurate shape are also disclosed.
US Patent applications 20050010131 and U.S. Pat. Nos. 6,331,166 and 6,699,206, all to Burbank et al., all of whose disclosures are incorporated herein by reference, describe a method and apparatus for precisely isolating a target lesion in a tissue, so that there is a high likelihood the lesion is removed with a margin. The apparatus comprises a biopsy instrument having a distal end (with respect to operator) adapted for entry into the patient's body, a longitudinal shaft, and a cutting element disposed along the shaft. The cutting element is actuatable between a radially retracted and extended position. Advantageously, the instrument is rotatable about its axis in the radially extended position to isolate a desired tissue specimen from surrounding tissue by defining a peripheral margin about the tissue specimen. Once the tissue specimen is isolated, it may be segmented by further manipulation of the cutting element, after which the tissue segments are preferably individually removed from the patient's body through a cannula or the like. Alternatively, the specimen may be encapsulated and removed as an intact piece.
U.S. Pat. No. 6,840,948 to Albrecht et al, whose disclosure is incorporated herein by reference, discloses a device and method for removal of tissue lesions, for example, in the breast, the liver and the lungs. The device includes a probe housing having a rotatable RF loop cutter mounted at the distal end of the probe. The RF loop cutter can include at least one electrode supplied with an RF actuating signal for cutting tissue. A rotational drive and specimen containment sheath can also be included. Real-time imaging is preferably used with the RF loop probe to assist in placement of the probe, and to more accurately assess a desired excision volume.
Ultrasound or ultrasonography is a medical imaging technique, using high frequency sound waves in the range of about 1 to 20 MHz and their echoes. The sound waves travel in the body and are reflected by interfaces between different types of tissues, such as between a healthy tissue and a denser cancerous tissue, or between a soft tissue and a bone. The ultrasound probe receives the reflected sound waves and the associated instrumentation calculates the distances from the probe to the reflecting boundaries.
Ultrasound probes are formed of piezoelectric crystal, which produces an electric signal in response to a pressure pulse. The shape of the probe determines its field of view, and the frequency of the emitted sound determines the minimal detectable object size. Generally, the probes are designed to move across the surface of the body. However, some probes are designed to be inserted through body. lumens, such as the vagina or the rectum, so as to get closer to the organ being examined.
The calculation of the distance, d, is based on the speed of sound in the tissue, v, (for example, in fat 1450 m/s, in blood 1570 m/s, in skull bone 4080 m/s, while the mean value for human soft tissue is 1540 m/s, which is similar to that of water) and the time of travel, t, usually measured in microseconds. Where a single probe is used as a transmitter and receiver, the time of travel, t, refers to the time it takes the sound signal to propagate through the tissue from the ultrasound probe to the reflecting interface and back to the ultrasound probe. Thus, in a homogeneous media, the distance may be calculated according to d=v t/2.
It will be appreciated that a predetermined offset needs to be considered, due to fixed electronic and mechanical delays. For example, in cases of measurements involving direct contact transducers, the offset compensates for transit time of the sound pulse through the transducer's wear-plate and the couplant layer, and for any electronic switching time or cable delays. The offset is determined as a part of instrument calibration procedures and is necessary for high accuracy. It will be further appreciated that when a single transducer transmits and receives, there is an additional dead time, which can be overcome by using at least two transducers, one transmitting and the other receiving.
A reflectance, R, may be defined, representing the energy that is being reflected. R depends on the impedance discontinuity between the different types of tissues across the interface, orR=(Z2−Z1)2/(Z2+Z1)2,
where Z1 is the acoustic impedance of the tissue in which the ultrasound pulse travels, and Z2 is the impedance of the tissue across the interface. In general, the acoustic impedance is the product of the density of a material, ρ, and the speed of sound in that material, v, so that,Z=ρv.
For tissues, which are essentially water-like, so that the speed of sound in them is essentially that of the speed of sound in water, the reflectance depends on the variation in tissue density ρ1 and ρ2, across the interface.
For example, in a human body, at ultrasound frequencies of several MHz, for example, 1-10 MHz, the density variation between fat and muscle tissue will lead to about 3% reflection because of the difference in ultrasonic impedance between the two types of tissue. Similarly, at these frequencies, a breast tumor, being denser than fat, will lead to a reflection of about 1%. Thus, the ultrasound technique is useful in identifying cancerous tumors. A radiologist may use the ultrasound imaging to guide a surgical tool, such as a biopsy needle or an incision instrument.
Before the early 1970's ultrasound imaging systems were able to record only the strong echoes arising from the outlines of an organ, but not the low-level echoes of the internal structure. Therefore liver scans, for instance, did not show possible carcinomas or other pathological states. In 1972 a refined imaging mode was introduced called gray-scale display, in which the internal texture of many organs became visible. In gray-scale display, low-level echoes are amplified and recorded together with the higher-level ones, giving many degrees of brightness. In consequence, ultrasound imaging became a useful tool for imaging tumors, for example, in the liver.
A development of recent years is a 3D ultrasound imaging, in which, several two-dimensional images are acquired by moving the probes across the body surface or by rotating probes, inserted into body lumens. The two-dimensional scans are then combined by specialized computer software to form 3D images.
In multiple-element probes, each element has a dedicated electric circuit, so that the beam can be “steered” by changing the timing in which each element sends out a pulse. Additionally, transducer-pulse controls allow the operator to set and change the frequency and duration of the ultrasound pulses, as well as the scan mode of the machine. A probe formed of array transducers has the ability to be steered as well as focused. By sequentially stimulating each element, the beams can be rapidly steered from the left to right, to produce a two-dimensional cross sectional image.
Contrast agents may be used in conjunction with ultrasound imaging, for example as taught by U.S. Pat. No. 6,280,704, to Schutt, et al., entitled, “Ultrasonic imaging system utilizing a long-persistence contrast agent,” whose disclosure is incorporated herein by reference.
A large number of techniques, other than ultrasound, are available today for tissue characterization, to determine the presence of abnormal tissue, for example, cancerous or pre-cancerous tissue. Many of these may be used with hand-held probes. Others use miniature probes that may be inserted into a body lumen or applied in minimally invasive surgery.
One of the methods used for tissue characterization is based on measurements of the tissue's electro-magnetic properties.
Commonly owned U.S. Pat. No. 6,813,515, to Hashimshony, entitled, “Method and system for examining tissue according to the dielectric properties thereof,” whose disclosure is incorporated herein by reference, describes a method and system for examining tissue in order to differentiate it from other tissue, according to the dielectric properties of the examined tissue. The method includes applying an electrical pulse to the tissue to be examined via a probe formed with an open cavity such that the probe generates an electrical fringe field in examined tissue within the cavity and produces a reflected electrical pulse therefrom with negligible radiation penetrating into other tissues or biological bodies near the examined tissue; detecting the reflected electrical pulse; and comparing electrical characteristics of the reflected electrical pulse with respect to the applied electrical pulse to provide an indication of the dielectric properties of the examined tissue.
Furthermore, commonly owned U.S. Patent Application 60/641,081, entitled, “Device and Method for Tissue Characterization in a Body Lumen, by an Endoscopic Electromagnetic Probe,” whose disclosure is incorporated herein by reference, discloses a device and method for tissue characterization in a body lumen, for the detection of abnormalities, using an electromagnetic probe, mounted on an endoscope. The endoscope may be designed for insertion in a body lumen, selected from the group consisting of an oral cavity, a gastrointestinal tract, a rectum, a colon, bronchi, a vagina, a cervix, a urinary tract, and blood vessels. Additionally, it may be designed for insertion in a trucar valve.
Electrical impedance imaging is another known imaging technique for detecting tumors. It involves systems in which the impedance between a point on the surface of the skin and some reference point on the body of a patient is determined. Sometimes, a multi-element probe, formed as a sheet with an array of electrical contacts is used, for obtaining a two-dimensional impedance map of the tissue, for example, the breast. The two-dimensional impedance map may be used, possibly in conjunction with other data, such as mammography, for the detection of cancer.
Rajshekhar, V. (“Continuous impedance monitoring during CT-guided stereotactic surgery: relative value in cystic and solid lesions,” Rajshekhar, V., British Journal of Neurosurgery, 1992, 6, 439-444) describes using an impedance probe with a single electrode to measure the impedance characteristics of lesions. The objective of the study was to use the measurements made in the lesions to determine the extent of the lesions and to localize the lesions more accurately. The probe was guided to the tumor by CT and four measurements were made within the lesion as the probe passed through the lesion. A biopsy of the lesion was performed using the outer sheath of the probe as a guide to position, after the probe itself was withdrawn.
U.S. Pat. No. 4,458,694, to Sollish, et al., entitled, “Apparatus and method for detection of tumors in tissue,” whose disclosure is incorporated herein by reference, relates to an apparatus for detecting tumors in human breast, based on the dielectric constants of localized regions of the breast tissue. The apparatus includes a probe, comprising a plurality of elements. The apparatus further includes means for applying an AC signal to the tissue, means for sensing electrical properties at each of the probe elements at different times, and signal processing circuitry, coupled to the sensing means, for comparing the electrical properties sensed at the different times. The apparatus thus provides an output of the dielectric constants of localized regions of breast tissue associated with the probe.
Similarly, U.S. Pat. No. 4,291,708 to Frei, et al., entitled, “Apparatus and method for detection of tumors in tissue,” whose disclosure is incorporated herein by reference, relates to apparatus for detecting tumors in human breast tissue, by the dielectric constants of a plurality of localized regions of human breast tissue.
U.S. Pat. Nos. 6,308,097, 6,055,452 and 5,810,742, to Pearlman, A. L., entitled, “Tissue characterization based on impedance images and on impedance measurements,” whose disclosures are incorporated herein by reference, describe apparatus for aiding in the identification of tissue type for an anomalous tissue in an impedance image. The device comprises: means for providing a polychromic emmitance map of a portion of the body; means for determining a plurality of polychromic measures from one or both of a portion of the body; and a display of an indication based on said plurality of polychromic measures.
Another known method of tissue characterization is by optical fluorescence spectroscopy. When a sample of large molecules is irradiated, for example, by laser light, it will absorb radiation, and various levels will be excited. Some of the excited states will return back substantially to the previous state, by elastic scattering, and some energy will be lost in internal conversion, collisions and other loss mechanisms. However, some excited states will create fluorescent radiation, which, due to the distribution of states, will give a characteristic wavelength distribution.
Some tumor-marking agents give well-structured fluorescence spectra, when irradiated by laser light. In particular, hematoporphyrin derivatives (HPD), give a well-structured fluorescence spectrum, when excited in the Soret band around 405 nm. The fluorescence spectrum shows typical peaks at about 630 and 690 nm, superimposed in practice on more unstructured tissue auto fluorescence. Other useful tumor-marking agents are dihematoporphyrin ether/ester (DHE), hematoporphyrin (HP), polyhematoporphyrin ester (PHE), and tetrasulfonated phthalocyanine (TSPC), when irradiated at 337 nm (N2 laser).
U.S. Pat. No. 5,115,137, to Andersson-Engels, et al, entitled, “Diagnosis by means of fluorescent light emission from tissue,” whose disclosure is incorporated herein by reference, relates to improved detection of properties of tissue by means of induced fluorescence of large molecules. The tissue character may then be evaluated from the observed large-molecule spectra. According to U.S. Pat. No. 5,115,137, the spectrum for tonsil cancer is clearly different from normal mucosa, due to endogenous porphyrins.
Similarly, U.S. Pat. No. 4,785,806, to Deckelbaum, entitled, “Laser ablation process and apparatus,” whose disclosure is incorporated herein by reference, describes a process and apparatus for ablating atherosclerotic or neoplastic tissues. Optical fibers direct low power light energy at a section of tissue to be ablated to cause the section to fluoresce. The fluorescence pattern is analyzed to determine whether the fluorescence frequency spectrum is representative of normal or abnormal tissue. A source of high power, ultraviolet, laser energy directed through an optical fiber at the section of tissue is fired only when the fluorometric analysis indicates that it is directed at abnormal tissue.
Additionally, U.S. Pat. No. 4,682,594, to Mok, entitled, “Probe-and fire lasers,” whose disclosure is incorporated herein by reference, describes a method and an apparatus of irradiating a treatment area within a body, such as blood vessel plaque. The method includes initially administering to the patient a non-toxic atheroma-enhancing reagent which causes the plaque to have a characteristic optical property when illuminated with a given radiation, introducing a catheter system including fiberoptic cable means into the artery such that the distal end thereof is operatively opposite the plaque site, introducing into the proximal end of the fiberoptic cable means the given radiation, photoelectrically sensing at the proximal end the characteristic optical property to generate a control signal, and directly under the control of the control signal transmitting via the cable means from the proximal end to the distal end, periodically occurring laser pulses until the characteristic optical property is no longer sensed.
U.S. Pat. No. 6,258,576, to Richards-Kortum, et al., entitled, “Diagnostic method and apparatus for cervical squamous intraepithelial lesions in vitro and in vivo using fluorescence spectroscopy,” whose disclosure is incorporated herein by reference, relates to the use of multiple illumination wavelengths in fluorescence spectroscopy for the diagnosis of cancer and precancer, for example, in the cervix. In this manner, it has been possible to (i) differentiate normal or inflamed tissue from squamous intraepithelial lesions (SILs) and (ii) differentiate high grade SILs from non-high grade SILs. The detection may be performed in vitro or in vivo. Multivariate statistical analysis has been employed to reduce the number of fluorescence excitation-emission wavelength pairs needed to re-develop algorithms that demonstrate a minimum decrease in classification accuracy. For example, the method of the aforementioned patent may comprise illuminating a tissue sample with electromagnetic radiation wavelengths of about 337 nm, 380 nm and 460 nm, to produce fluorescence; detecting a plurality of discrete emission wavelengths from the fluorescence; and calculating from the emission wavelengths a probability that the tissue sample belongs in particular tissue classification.
Commonly owned U.S. Patent Application 2003/01383786, to Hashimshony, entitled, “Method and apparatus for examining tissue for predefined target cells, particularly cancerous cells, and a probe useful for such method and apparatus,” whose disclosure is incorporated herein by reference, teaches a method apparatus and probe for examining tissue and characterizing its type according to measured changes in optical characteristics of the examined tissue. In a preferred embodiment of this method the tissue to be examined is subject to a contrast agent containing small particles of a physical element conjugated with a biological carrier selectively bindable to the target cells. Additionally, energy pulses are applied to the examined tissue, and the changes in impedance and/or the optical characteristics produced by the applied energy pulses are detected and utilized for determining the presence of the target cells in the examined tissue. Furthermore, in a preferred embodiment, the applied energy pulses include laser pulses, and the physical element conjugated with a biological carrier is a light-sensitive semiconductor having impedance which substantially decrease in the presence of light. Moreover, the same probe used for detecting the targeted cells, may also be used for destroying the cells so targeted.
Optical reflectance spectroscopy may also be used. Its application for tissue characterization is described, for example, in http://www.sbsplimb.nichd.nih.gov/html/spectroscopy.html, downloaded on Mar. 15, 2005. It describes an optical reflectance spectroscopy (ORS) device for measuring the thickness of the epithelial layer, and an evaluation technique based on oblique angle reflectance spectroscopy that allows assessment of the scattering and absorption properties of the epithelium and stroma, thus providing information on chronic oral epithelial tissue inflammation, which is considered a potential diagnostic precursor to oral cancer.
Another known method for tissue characterization is magnetic resonance imaging (MRI), which is based on the absorption and emission of energy in the radio frequency range of the electromagnetic spectrum, by nuclei having unpaired spins.
Conventional MRI is a large-apparatus, for whole body imaging, having:
i. a primary magnet, which produces the Bo field for the imaging procedure;
ii. gradient coils for producing a gradient in Bo;
iii. an RF coil, for producing the B1 magnetic field, necessary to rotate the spins by 90° or 180° and for detecting the MRI signal; and
iv. a computer, for controlling the components of the MRI imager.
Generally, the magnet is a large horizontal bore superconducting magnet, which provides a homogeneous magnetic field in an internal region within the magnet. A patient or object to be imaged is usually positioned in the homogeneous field region located in the central air gap for imaging. A typical gradient coil system comprises an anti-Helmholtz type of coil. These are two parallel ring shaped coils, around the z axis. Current in each of the two coils flows in opposite directions creating a magnetic field gradient between the two coils.
The RF coil creates a B1 field, which rotates the net magnetization in a pulse sequence. The RF coils may be: 1) transmit and receive coils, 2) receive only coils, and 3) transmit only coils.
As described hereinabove, the MRI relies on a magnetic field in an internal region within the magnet. As such, it is unsuitable as a handheld probe or an endoscopic probe, because the tissue to be imaged has to be in the internal region of the imager,
This problem has been resolved by U.S. Pat. No. 5,572,132, to Pulyer, et al., entitled, “MRI probe for external imaging,” whose disclosure is incorporated herein by reference, which describes an MRI spectroscopic probe having an external background magnetic field B0 (as opposed to the internal background magnetic filed of the large horizontal bore superconducting magnet.). Thus, an MRI catheter for endoscopical imaging of tissue of the artery wall, rectum, urinal tract, intestine, esophagus, nasal passages, vagina and other biomedical applications may be constructed. The probe comprises (i) a miniature primary magnet having a longitudinal axis and an external surface extending in the axial direction, and (ii) a RF coil surrounding and proximal to said surface. The primary magnet is structured and configured to provide a symmetrical, preferably cylindrically shaped, homogeneous field region external to the surface of the magnet. The RF coil receives NMR signals from excited nuclei. For imaging, one or more gradient coils are provided to spatially encode the nuclear spins of nuclei excited by an RF coil, which may be the same coil used for receiving NMR signals or another RF coil.
Additionally, commonly owned U.S. Patent Application 2005/0021019 to Hashimshony et al., entitled “Method and apparatus for examining substance, particularly tissue, to characterize its type,” whose disclosure is incorporated herein by reference, describes a method and apparatus for examining a substance volume to characterize its type, by: applying a polarizing magnetic field through the examined substance: applying RF pulses locally to the examined substance volume such as to invoke electrical impedance (EI) responses signals corresponding to the electrical impedance of the substance, and magnetic resonance (MR) responses signals corresponding to the MR properties of the substance; detecting the EI and MR response signals; and utilizing the detected response signals for characterizing the examined substance volume type.
Contrast agents may be used in conjunction with MRI. For example, U.S. Pat. No. 6,315,981 to Unger, entitled, “Gas filled microspheres as magnetic resonance imaging contrast agents,” whose disclosure is incorporated herein by reference, describes the use of gas filled microspheres as contrast agents for MRI.
Temperature imaging for locating and detecting neoplastic tissue is also known. In the 1950's, it was discovered that the surface temperature of skin in the area of a malignant tumor exhibited a higher temperature than that expected of healthy tissue. Thus, by measuring body skin temperatures, it became possible to screen for the existence of abnormal body activity such as cancerous tumor growth. With the development of liquid crystals and methods of forming temperature responsive chemical substrates, contact thermometry became a reality along with its use in medical applications. Devices employing contact thermometry could sense and display temperature changes through indicators which changed colors, either permanently or temporarily, when placed in direct physical contact with a surface such as skin, reflecting a temperature at or near the point of contact. An abnormal reading would alert a user to the need for closer, more detailed examination of the region in question. However, the art in this area has been directed primarily at sensing and displaying temperatures on exterior skin surfaces. Thus, for example, U.S. Pat. No. 3,830,224, to Vanzetti et al., whose disclosure is incorporated herein by reference, disclosed the placement of temperature responsive, color changing liquid crystals at various points in a brassiere for the purpose of detecting the existence of breast cancer, while US Patent RE 32,000, to Sagi, entitled, “Device for Use in Early Detection of Breast Cancer,” whose disclosure is incorporated herein by reference, disclosed the use of radially arranged rows of temperature responsive indicators, deposited on a disc for insertion into the breast-receiving cups of a brassiere for the same purpose.
U.S. Pat. No. 6,135,968, to Brounstein, entitled, “Differential temperature measuring device and method”, whose disclosure is incorporated herein by reference, describes a device and method for sensing temperatures at internal body locations non-surgically accessible only through body orifices. The device is particularly useful in medical applications such as screening for cancer and other abnormal biological activity signaled by an increase in temperature at a selected site. As applied to prostate examinations, the device is temporarily, adhesively affixed to a user's fingertip or to a mechanical probe. In the preferred embodiment, the device includes two temperature-sensing elements, which may include a plurality of chemical indicators. Each indicator changes color in response to detection of a predetermined particular temperature. When properly aligned and installed, the first element is located on the palmar surface of the fingertip while the second element is located on the dorsal surface of the fingertip. After an examination glove has been donned over the fingertip carrying the device, a prostate examination is performed during which the first element is brought into constant but brief contact with the prostate region and the second element is similarly, simultaneously brought into contact with a dermal surface opposing the prostate region. Upon withdrawal of the fingertip from the rectum and removal of the glove, the two temperature sensing elements may be visually examined in order to determine the temperatures detected by each one. A significant difference in observed temperatures indicates the possibility of abnormal biological activity and the need for further diagnostic or medical procedures.
Infrared thermography is a temperature imaging technique, which measures thermal energy emitted from the body surface without contact, quickly and dynamically, and produces a temperature image for analysis. Harzbecker K, et al. report, based on thermic observations in 63 patients and a control experiment in 15 persons, on experiences with thermography in the diagnosis of diseases, which are localized more profoundly in the thoracic cavity. (Harzbecker K, et al., “Thermographic thorax diagnostics,” Z Gesamte Inn Med. Feb. 1, 1978;33(3):78-80.)
Similarly, Dexter L I, Kondrat'ev V B. report data concerning the use of lymphography and thermography for the purpose of establishing a differential diagnosis in 42 patients with edema of the lower limbs of a different origin. A comparative estimation of different methods of the differential diagnosis indicated the advantages of infrared thermography. (Dexter L I, Kondrat'ev V B., “Thermography in differential diagnosis of lymphostasis in the lower limbs,” Vestn Khir Im I I Grek. June 1976; 116(6):60-4.)
Various means for minimally invasive surgical removal, of a breast tumor and other tumors in a soft tissue are known.
For example, U.S. Pat. No. 6,375,634, to Carroll, entitled, apparatus and method to encapsulate, kill and remove malignancies, including selectively increasing absorption of x-rays and increasing free-radical damage to residual tumors targeted by ionizing and non-ionizing radiation therapy”, whose disclosure is incorporated herein by reference, describes a coaxial bipolar needle electrode for applying radio-frequency diathermal heat.
U.S. Pat. No. 6,840,948 to Albrecht, et al. entitled, “Device for removal of tissue lesions,” whose disclosure is incorporated herein by reference, describes an excisional biopsy device and method for excision and removal of neoplasms under real-time image guidance with minimal disruption of normal tissue while providing an optimal specimen to assess the completeness of the excision. The device and method are minimally invasive, and are used to remove cancerous lesions from soft tissue, including breast tissue, and are a less invasive alternative to open lumpectomy. The invention provides an RF loop for excision and removal of breast lesions which promotes hemostasis during excision through electrosurgical coagulation of blood vessels and channels to supply pressure and hemostatic fluids to the tissue cavity.
The method includes is as follows: The mass is localized, and the tunneling trajectory is determined. The skin is excised, and tunneling is begun by activating and using the semi-circular RF tunneling electrode. After tunneling is completed, but prior to cutting a sphere, the coordinates of the excision specimen are confirmed, preferably with the assistance of computer aided imaging and guidance technology. The semi-circular rotational electrode blade of the RF loop is then activated and used to cut the sphere, and is rotated by the drive electrical cables attached to the power drive. Simultaneously, the tissue is immobilized and any blood is aspirated by vacuum. As the RF loop is rotated, it pulls along the containment sheath or bag that surrounds the spherical specimen. After the sphere is fully cut, the RF loop is held in place and the containment sheath is pulled taught around the sphere by a draw cord to reduce the sphere's volume to aid in its removal. The device and sphere are then removed from the body simultaneously.
US Patent Application 20020120265, to Fowler, entitled, “Symmetric conization electrocautery device,” whose disclosure is incorporated herein by reference, describes a tissue electrocautery device that accommodates anatomical structures lying at more than one longitudinal axes. Such a circumstance is encountered when attempting to perform symmetric tissue electrocautery of an endocervical canal where the longitudinal axis of the vaginal vault is at an angle to the longitudinal axis of the endocervical canal. The device of the present invention uses a hollow housing, elongate along a first longitudinal axis, having a proximal portion with a proximal end and a distal end, and includes a distal portion from the distal end. The distal portion is elongate along a second longitudinal axis and pivotable in relation to the proximal portion at a selectable angle to the first longitudinal axis. Within the housing is a rotatable electrically conducting mechanism, adapted to conduct electrocautery energy from an electrode proximal to the housing proximal portion to a coupling proximate the distal portion, while rotating the coupling with a removable handle proximal to the housing proximal portion. The electrical energy is delivered to an electrocautery head, carrying an electrocautery wire, operably electrically engageable with the coupling and rotatable around a longitudinal axis parallel the second longitudinal axis, electrocauterizing tissue of a human patient while rotating around its longitudinal axis.
In spite of these works, clean removal of malignancies, surrounded by definite and sufficient clean margins, remains an elusive goal.